Such apparatus are used in the food industry, for example, to separate the fat cover and/or the rind of a meat product from the quality meat. Depending on the purpose and on the kind of product, different tools such as rollers or knife blades are used for the removal, which are pressed toward the moving product transversely to the product conveying direction. It is necessary for a correct function of such a removal apparatus that the pressure of the removal tool onto the product surface is maintained during the total removal procedure.
Spring devices are therefore provided in conventional removal apparatus to pretension the removal tool toward the product surface. There is, however, the problem here that the spring force is dependent on the deflection of the spring device that is on the position of the removal tool relative to a base position, and the pressing force thus varies in the event of an irregular product thickness. This can have the result that the removal of the surface layer does not run ideally.
It is therefore a feature of the invention to ensure a uniform removal of the surface layer in an apparatus of the named kind also for products of irregular thickness.
The above referenced feature is provided by an apparatus for removing a surface layer from food products having a product feed which feeds a product to be processed along a product conveying direction to a removal tool. The product is pressed with a component perpendicular to the product conveying direction toward an operative surface of the removal tool.
In accordance with an embodiment of the invention, the position of the removal tool relative to the product feed is adjustable by means of an adjustment apparatus, with a control unit associated with the adjustment apparatus being designed to adjust the position of the removal tool relative to the product feed in dependence on the contour of the product. The pressing force can be varied as desired by the active adjustment of the relative position between the product feed—for example a product support surface—and the removal tool since said pressing force ultimately depends on the spacing between the operative surface of the removal tool and the corresponding counter-force which is associated with the product feed. In this respect, it does not play any role whether a spring device is additionally also provided for pressing on which is influenced in its deflection by the adjustment procedure or whether the relative position between the removal tool and the product feed is fixed, apart from the adjustment procedure, and the pressing force is ultimately based on the elasticity of the product. Depending on the application, the adjustment apparatus can move the removal tool itself or move a corresponding counter-surface of the product feed. The adjustment of the relative position can also take place in that both the removal tool and an associated counter-surface of the product feed are moved by the adjustment apparatus.
Provision is made in an embodiment that the relative position between a counter-surface of the product feed and the removal tool is adjustable.
Provision can furthermore be made that the counter-surface is formed at a pressing apparatus, with the pressing apparatus in particular including a pressing roller.
In accordance with a possible embodiment, the relative position is adjustable between a pressing apparatus and a product support surface of the product feed. In this respect, in particular the removal tool is arranged in a cut-out or recess of the product support surface.
Provision can furthermore be made that the product feed includes a pressing apparatus which is designed to press the product toward a product support surface of the product fed, with in particular the removal tool being arranged in a cut-out or recess of the product support surface.
In an embodiment, the removal tool may be arranged in a fixed position with respect to the adjustment direction relative to a product support surface of the product feed. This is, however, not compulsory. Alternatively, the removal tool can be adjustable with respect to the product support surface.
In an embodiment, the control unit may be designed to continuously adjust a counter-surface of the product feed and/or the operative surface of the removal tool to follow the contour of the product during the removal procedure. In other words, the adjustment apparatus guides the counter-surface or the removal tool continuously along the surface of the product during the removal procedure. The counter-surface or the removal tool therefore does not passively follow the product surface as with usual removal apparatus, but is rather actively guided along it. In this manner, an unchanging pressing force and thus an unchanging removal effect can be achieved during the total removal procedure. The counter-surface is in particular formed at a pressing apparatus, e.g. at a pressing roller, which can be driven and thus can also serve as a conveying roller or it can be not driven and can be freely rotatable.
In accordance with an embodiment, the spacing of a counter-surface of the product feed and/or of the operative surface of the removal tool from a product support surface of the product feed can be adjusted by means of the adjustment apparatus. The product support surface can e.g. be the surface of a belt conveyor which simultaneously also serves for the product advance. Alternatively, a static product support surface could also be provided.
Furthermore, a detection device for determining the contour of the product can be provided which is connected to the control unit and which in particular works in a contactless manner. The control unit is thus able to carry out the position adjustment with reference to the specifically measured contour of the product just to be processed, whereby a particularly exact following adjustment of a counter-surface and/or of the removal tool can be achieved.
The detection device can include at least one distance measuring sensor, in particular an ultrasound based sensor. A reliable determination of the product contour is hereby possible without piercing or cutting into the product or otherwise damaging it.
A contactless distance detection can take place in an optical manner in accordance with an embodiment of the invention. An optical detection device can be provided, for example which is based on the triangulation principle or on the light sectioning process. In particular, at least one line projector with a laser as a light source can be used in conjunction with at least one camera for observing the projected line on the product in order thus to determine the product contour by the line offset. A further possibility for contactless contour detection is the use of an X-ray scanner which is able to determine the inner structure of a product using density differences. The portion of the structure information related to the outer contour can be extracted from this exhaustive structure information. The use of an X-ray scanner is in particular suitable with applications in which the inner structure of the product anyway has to be determined—for example to observe an exact product portion weight.
It is generally also conceivable, in accordance with an independent aspect, to press the product toward a product support surface from above, e.g. by means of a pressing roller or a conveying roller, with a knife blade which is vertically adjustable in dependence on the contour removing a lower surface layer of the product while the product is conveyed in the direction of the knife blade.
In accordance with an embodiment, the removal tool comes into enragement with the product surface from below in order thus to remove a lower surface layer of the product. In this case, gravity can assist or even completely provide the pressing force. The removal tool can be positioned in a cut-out or recess of the corresponding product support surface for this purpose. Depending on the application, the lower removal tool can in this respect be vertically adjustable or an upper counter-surface, e.g. a top section of the product feed, can be adjusted in dependence on the product contour with a fixed-position removal tool. In principle in accordance with the invention, at least two removal tools can be provided which can be adjusted in dependence on the contour and which are operative at oppositely disposed product sides.
In accordance with an embodiment, the removal tool includes a tool for defatting, skinning and/or derinding. The invention allows a particularly effective cutting of the rind and/or of the fat cover of a meat product from the quality meat component lying thereunder by providing an unchanging pressing force.
In accordance with an embodiment, the removal tool includes at least one roller rotatable about an axis of rotation extending transversely to the product conveying direction. In such an embodiment, fat is removed, for example, in that it is led through a restriction between the rotatable roller and a support surface of a product conveyor. The pressing force with which the roller is pressed toward the product surface is in this respect predefined by the height of the restriction. The pressing force can be reduced as required by increasing this height by means of a positional adjustment of the roller. The roller can have a ribbing such as is known in the field of defatting machines. The roller can alternatively be a pressing roller which presses the product toward a product support surface in which the removal tool is arranged.
In accordance with an embodiment, the removal tool includes at least one knife or a blade, with a conveying device preferably formed as a roller in particular being disposed before the knife or the blade in the product conveying direction.
The knife or the blade may be arranged in a recess or cut-out of the product support surface, in particular together with the additional conveying device preferably formed as a feed roller. The knife or blade and the feed roller are consequently located beneath the product and the feed roller serves to feed the surface layer to be removed to the cutting edge of the knife or blade safely and reliably. The knife or the blade and optionally also the feed roller can be adjustable, with, however, this preferably only taking place in the sense of a one-time machine setting for the respective product and having nothing to do with the adjustment in dependence on the product contour in accordance with the invention.
The knife or the blade can be provided with an apparatus which serves to deflect the cut-off surface layer, e.g. a rind, downwardly, e.g. into a collection container.
The adjustment apparatus may include a motorized actuating drive. A sufficiently fast and reliable following adjustment of the removal tool and/or of a counter surface of the product feed can hereby be ensured.
The actuating drive can in particular include a controllable electric motor by means of which a fast and exact positional adjustment can be achieved.
In accordance with a further embodiment of the invention, a pressing apparatus of the product feed and/or the removal tool is attached to a pivot arm, with the pressing apparatus and/or the removal tool being able to be raised and lowered with respect to a product support surface of the product feed by means of the adjustment apparatus. The pivot arm can in this respect form a lever for amplifying the adjustment force.
The adjustment apparatus can be designed to adjust the relative position between the product feed and the removal tool furthermore in dependence on a quality of the product. It can, for example, be desirable to predefine different pressing forces for different types of product. The removal quality can thus be further optimized.
The removal tool can generally be adjusted relative to a support surface or support plane for the product or relative to a counter-surface located above the support surface, e.g. formed at a pressing apparatus, with it not playing any role whether the removal tool, the support surface or the counter-surface or both components are moved, i.e. it is, for example, also possible to adjust the support surface or the counter-surface in the vertical direction in dependence on the contour and so to press the product toward a removal tool fixed in the vertical direction by means of the adjustable support surface.
The invention furthermore relates to a method for removing a surface layer from food products, wherein a contour of a product to be processed is determined, the product is fed along a product conveying direction to a removal tool such that the product is pressed with a component perpendicular to the product conveying direction toward an operative surface of the removal tool and the relative position between the product feed and the removal tool is adjusted in dependence on the determined contour of the product by means of an adjustment apparatus.
The position of a pressing apparatus of the product feed can in particular be adjusted to follow the contour of the product during the removal procedure.
In accordance with an embodiment, the contour of the total product is determined before the start of the removal procedure. This can in particular be advantageous if the product contour anyway has to be determined for other purposes.
Alternatively, the contour of the product can also be determined point-wise or section-wise during the removal procedure. Such a contour detection “on the fly” can be advantageous for specific applications.
The invention will be described in the following by way of example with reference to the drawings.